Compressor governor



5] l INVENTOR. Mas UHR/arman A TTORNEYS.

N. A. cHRlSTl-:NSEN

OOMPREssOR GOVERNOR Filed July 18. 1924 Nov. l2, 1929.

Patented Nov. 12, `1929 UNITED STATES NInLs A. cHRIsTENsnN, or MILWAUKEE, WISCONSIN COMPRESSOR GOVERNOR Appncation nieu my 1e,

other parts associatedwith it or with the engine for driving it. The object of this invention is to provide a compressor governor ofthe automaticpressure relief type which may be placed in any suitable position in the discharge line of the compressor between the discharge valve and the reservoir, thereby permittlng the device to be readily installed without consideration of the design of other parts of the compressing apparatus or its r driving means.

The invention further consists in the several features hereinafter set forth, and more particularly defined by claims at the conclusion hereof.

In the drawings: Fig. lis a side elevation view of a compressor governor embodying the invention, parts being broken away yand parts being shown in section; f f

` Fig. 2 is a plan View taken of the structure i shown in Fig. 1, with the top cover removed; f

i Fig. 3 is a sectional view taken on the line 3-3 ofFig. 2, showing the parts of the governor in one position;

Fig..4: is a view similar to Fig. 3L showing the parts of the governor in another position. The device embodying the invention may be used in connection with any suitable compressor andis shown as associated with the discharge pipe 5 from said compressor which 115 conducts the compressed air to the reservoir, notshown, past the usual check valve 6 in the' discharge pipe. The governor hereinafter explained is designed to provide a valvecontrolled vent opening from the discharge `5o pipe 5,; or anequivalent part leading to the 1924. serialy No. 726,876.

reservoir, so as to provide a vent opening whereby when the pressure in the reservoir reaches a predetermined maximum the continuously running compressor will cease to supply the reservoir with compressed4 air. 55 To accomplish this purpose the governor mechanism includes a relief valve 7 which controls the passage of air from the pipe 5', here shown as a branch of the pipe to a passage 9 leading to atmosphere, either direct 60 or through a pipe 10, said valve 7 rbeing normally held closed by a spring 8 and being moved to kopen position by mechanism operable through variations in the. pressure existing in the reservoir or system.

To'effect the opening of the valve 7 a piston 11 is slidably mounted in a small cylinder 1 2 inthe governor casing, said cylinder having a head 13, here shown in the form of a disk sweated into the casing, the piston having 70 a cylindrical projection 14.` working in `a centrally disposed opening in the head 13. This piston is `actuated by compressed air from the system, and the passage of compressedk air tothe cylinder, 12 is con- 75 trolled by a primary air valve 15.

The air valve 15 is preferably of the needle type, mounted in a cage formed by a plug 16 in threaded engagement with the casing, said valve controlling the passage of air from a r30 centrally disposed conduit 17 in the plugto a transverse passage 18 which communicates with a passage 19 in the main casing leading ytothe upper end of the cylinder 12. n

The seat20 for the valve 15 is formed in l85 the upper end ofthe passage 17 and the valve is normally held against its seat by a spring 21 interposed between the enlarged lower headed end of the valve and a removable screw-plug 22. ,A

The passage 17 is formed of two diameters, the larger one housing the lower end of the valve and the spring, and the upper one forming al guide bore for thestem of the valve 15, which stem has a flattened portion 23 to allow 95 passage of air through the upper part of the passage 17 past the seat 2O when the valve is open. i I The plug 16projects into a control chamber-,or reservoir 24 which has communication vlo .Cari

Ci held in inoperative position by a-springi with the passage 8 connected with the pipe through a conduit 25, chamber 26 and a passage 28 controlled by a check valve 29. The passage 28 is formed in a removable screw-plug 30 andrnounted in the casing between the chamber 26 and the reservoir Q4, said chamberQ having a screvvfplugv 3l closing its lower end andpermitting inser-tionvor removal of the plug 30.

A check valve 29 has a head adapted to seat against the upper end ci the plugSO, and has its stem passing through the passage 28, with its lower end provided with a nut 32 to limit its movement, "vhll nut has Vradially disposed grooves 33 therein to permit the passage of vair from the chamber 256 to the Cendrill- 28..-

TheE reservoir M24 Vhasua drain opening 34 closed by a removable screyvplug 35. lllhen the compressor is functioning normally it ,yvill be noted that the control reservoir .24 Willbe chargedwith air at discharge or reservoirrpressfure, .since theair from the discharge pipe line J5is thenfree to pass from said pipe tozpipe l5,co nduits 8 and 25, chainber QSand passage28, to the reservoir24, said pressure .ser ingtoleep check valve 29 lopen. lllhenthe .valve 1 5 .is open the compressed rinthe reservoir 24 passes therefrom through passages .17, 1S and 19 to the cylinderv l2 and actson the piston ll to move saineloivn to openthe valve U7, the opening .of said valveinirnediately reducing the pressures in the conduits'frand 25 and chamber 26, thereby causing the check valve 29 to close, this movement or' the valve T by `the piston l1 ybeing ell'ected because the area of the piste; ll is greater tlianfthatof the headot the valve and consequently the ydierential pressure `through the transmission of compressed air `troni' the reservoir 24 to the @vlinderlffects .the Opening 0f the valve 7 against `the pressure yon its head .and the spring 8l` and causes the check valve 29 to Icut on". the discharge et air from the reservoir 24 into the chamber 26. i s

The-,laws for sl'etne the opening ofthe primary air valve l5 consists of a pin engageable with the upper end of the valve l5 and extending through an opening in the Plug' 1,6 all@ Plol@ Seele ed Pistons@ l 'G1' Wlivl iS .nivo 'F te its ,ends :on a pin 37 and is :normally Lsing' slightly beyond the ged byla-be l crank ly mounted interme- 'llhis ,lever 37 not :only serves to engage the pin so as to open the valve l5, butlis also a ho ling lever in that it ser res to :hold -the valve 'T open when the other-mechanism hereinatter described, andactuated by the pres si e the reservoir, actuates said lever 8T.

:in operating lever is pivotally moi-.nted on a pin 39 carried by ears on the governor casing 40 and is operated by Aa rod 41 which a .tallied upper enel 42 provided with a.

The rod 4l is moved-in one direction, that s is, upward, by lluid-pressure-operated means, comprising a cap member 48 with which the lower endet` said rod is in contact, and forming with Aan end plate 49 and a bellows 50,` connected at one end to said cap and Aat its other endrto said plate in a iluidtight manner, a diaphragm or pressure chamber 5l in communication with the reservoir .or not shown, throughs). pipe A52. Thus,

vvrhen air is introduced into the chamber 5l from the reservoir, it Will tend to move the cap member` 48 upward or outward and hence move the .rod 4l upward and causethe en d ot lever 8S, vwith which it `is connectedyto swing upward past its fulcrurn center and the springs then pull in the opposite direction to cause the lever to movedovvnfthe amount olost-motion refer-red to. 'The rod 41 is moved in the oppositedirectionby ay spring :3B-interposed between a part ofthegovernor casing and nut 5401i said rod rwhich spring causes said rod to move ',dovvnvvardlyin *ope position to the pressure of the air in the chamber 5l and thus causethe end ofthe lever 38 with which it isconnected to swing downwardly past its fulcrum center, and the springs pulling inthe opposite direction cause the lever to movezup, as shovvn in full lines in Fig. l, the amount of lost-motion referred to. The tension ofthe spring-53 is adjusted to such a value that -it holds the lever 3S in its upper or inoperative position against the pressure in the chamberv 5l until the reservoir pressure builds up to a certain predetermined maximum value. The tree end of the lever 38 on its downward swinging movement engages the pin 86 to move the same andconsequently the primary air .valve l5 downwardly to open said valve and hold it ope-n When the pressure inthe reservoir has attained a predetermined maximum value.

ln order that the primary valve l5 .will notI be held open underslifrhtdeviations in `pressure in the reservoir7 a trigger or latch 55 cooperates with thefbell crank levei37. This latch is in the form of a lever pivotally mountedvat its lovver end on a pin 56 carried by the casing l.and normally moved Etovvard the lever 3.7 by a spring 5.7. The latch V has a notch'58 ivith which the .pointed rree end o9 of the lever 37 engages, whereby.V said latch 55 holds` the lev-er 37 in Aal valve opening position when the operating llever 38 .has moved said lever 'vtothis position.

The llever 3.7 also has the function of'hold-- ing the piston l2 in its lover or valve-open AIl() ing position when engaged bythe latch 55, since the pin or projection 14 on the piston y is in line with the lever and enga ed therebv,

charge )i 9e 5 is o )en to atmos here through` the opening of the valve 7. Thus, the opening of the valve 15 by the lever 37 occurs first, :followed by the opening of the valve 7 by the piston 11 and the holding of said valve 7 open by the lever 37, the function of the lever 37 being to open the primary air valve and then hold the main relief valve 7 in an open position until such time as the pressure in the reservoir has been reduced to al condition Where it is again necessary to build up the pressure in the reservoir with more compressed air.

The latch or trigger 55 also has a curved or beveled tace 60 at its upper end engaged by the end Glof the lever 38 on its upward swinging movement so as to release said latch from locking engagement with the lever 37 and thus allow the primary air valve 15 to close and hence cut oli' the supply ot compressed air to the cylinder 12 and permit the spring 8 to close the valve 7 since the presf sure upon the piston 11 in the cylinder 12 is not maintained for any length ot time due to seepage of air around the pin 36 and the projection 14 ot the piston.

lll/lith the construction above described, when the pressure in the reservoir, and hence the chamber 51, reaches a predetermined mai:- imum value, the diaphragm, including the member 48, moves the rod l1 upward and swings the free end 61 ot the lever 38 downard, the lever 38 upon swinging past horizontal position being given a quick and strong throw by the springs ll5 and coming in contact with the lever 37 swings the same down, irst into Contact with the pin 36 which opens the valve 15 thereby admitting coinpressed air to the cylinder 12, moving theL piston 11 down with the consequent opening of the valve 7, and as the lever 37 continues to move down it is engaged by the trigger or latch 55 which keeps it in position to hold the piston 11 and consequently the relief valve 7 open after the lever 38 moves away -from the lever 37. Thus the continuously running compressor simply draws in air and pushes out the air past its discharge valve into the pipe 5 andthence to atmosphere, as

previously explained, until such time as the pressure in the system has dropped to a predetermined minimum value, such that there is less force on the diaphragm or member 418, which then permits the spring 53 to come into action and move the levert-38 in the oppositedirection, causing the end 61 otsaid lever to swing upward when the lost-motion Aagain comes into play and the springs l5 `again impart a quick and strong orce'to rthe lever to move saidr end of said lever against the u n 3er end ot' the latch 55 to cause :n

`its release, which lever then moves tothe disengaged position under the action oi its spring `57 and the release oflever 55 also permits the spring 39 to inovelever 37 upwardlyr` away from the projection 14 and the pin 36, thereby permitting the valve 15 to itsclt and the spring 8 to return the falve "7 to a closed position with the consequent movement ot the piston 11 to its upper position, thereby shuttinfT oli" further venting ot the compressed air from the pipe 5 through the pipe 5 to the passage 9, and under which vconditions compressed air from the compressor then passes through the pipe 5 past the check valve 6 to the reservoir. Thus, the springs l5 serve to produce a quick action on the lever `37-to open' the valve 15 and asimilar quick action on the latch to release the lever '37, and the opening of the valve `7 serves `to reduce the power necessary to keep the ycompressor ruiming, since under these conditions the compressor is only working against the resistance off the air in its travel pastthe discharge valve, usually springseated, of the compressor normal compressing stroke.

4The studs 47 and similar studs G2 secure the removable cover 63 in place on the casing. The springs 37 and'57 are each held in place by having` one end seated in an opening in the lover with which it is associated and the other end bearing against a plate 64 secured tothe governor casing by a screw 65.

lllhile the terms downward and upward77 have been used relative to the descriptionfo'f the direction oi movement oi the valves andthe levers associated with them, it will be understood that such terms are only relative and ythat it is possible to place the governor in other than an upright position without interfering with its operation,it being understood that where the device is not placed upright a light si'ning' may be associated with on `its otherwise f the check valve 29 to tend to close the same.

I desired it to be understood that this invention is not to be limited to any particular form or arrangement ot parts except in so far as such limitations are included in the claims or made necessary by the prior art.

W' hat I claim as my invention is:

1. In a compressor control, the combination with the discharge line oin a compressor, of a relief valve in said line, fluid-pressureoperated means for opening said rclie't valve, a primary valve for controlling the operation of said fluid-pressure-operated means, and means for controlling the operation of said primary valve including a lever for opening said primary valve, a latch engageable with said lever when the lever has moved the pri mary valve to open position to hold said primary valve open, and means responsive to pressure in the reservoir for movingfsaid lever s valve-opening position when the pressure in the reservoir reaches e predetermined limit.

if. En a compressor eontroh'the combination with the discharge line of e compressor, of e. relief valve in said line, iuid-pressureoperated means for opening seid relief valve While the compressor is running, a primary ,lo valve for controlling the operation of said iuid-pressure-operated means, means or opening sind primary valve and holding the relief Valve in open position including a lever and e ieteh associated therewith, and means 15 responsive to the pressure in the system for actueting said lever and releasing said latch.

3. In e compressor control, the combination With'the discharge line of s compressor, of a relief Valve in said iine, a control reservoir D communicating with said line, e check Valve closing connnunieetion with said line when seid relief Valve is open, a cylindera a Velvecontrolled passage between seid reservoir and cylinder, a piston in seid cylinderactuated by the pressure in seid reservoir 'for opening said valve against discharge line pressure, e control valve for said passage, rund means responsive to p essure inthe system for actuating said control valve.

gc, 4. In ay compressor control7 the combination y'ith the discharge line of u compressor, of a relier' valve in said line7 s Control reservoir communica-ting with seid line, a check valve closing Communication with seid line when seid relief Valve is open, e Cylinder, a valvecontrolled passage between said reservoir and cylinder, ai piston in seid cylinder actuated by the pressure in seid rreservoir for Opening said valve against discharge line pressure, a

4D Control Valve for said passa-ge, and meansl re sponsive to pressureV in the system for actuatir seid control valve, said means also ineluding mechanism forV holding said relief Valve open until the pressure inthe system reaches a predetermined minimum vlue.

in testimony whereof, l alflix my signature'.

NIELS A. CHRISTENSEN. 

